Lens Fungus and Me

Rodinal Addict · 08-19-2004

Greetings Comrades!
I now have three FED lenses, that came with the two FEDs I've recently bought. I'm noticing some odd threadlike things apparently in between the glass elements on one lens, ans a roundish spot on another one. Is this the dreaded fungus that I see mentioned around? Where does fungus (in lenses) come from, can it affect images, and can I remove it?

JohnM · 08-19-2004

1) Almost certainly fungus.

2) Generally comes from too much moisture or humidity when the camera or lens is stored for a long period of time. (Can take years to develop).

3) In the beginning, it generally doesn't affect the image. As time goes on, you lose clarity, gain flare, etc.

4) Yes, sort of. If you catch it early, you can clean it. Some people say use vinegar, some say cold cream, some say put the camera in sunlight. I've used cold cream and it worked to kill the fungus - in one case, the camera was fine afterwards. In another, the acid from the fungus had already etched the glass badly and the camera was a loss. Honestly, try the lenses out. See what the results are - your best bet is to use the lenses for whatever their worth or replace them.

bmattock · 08-20-2004

Also remember - fungus is a plant-like orgranism that spreads spores. Common wisdom is to keep lenses that have active fungus colonies away from lenses that don't. Dunno if it is true, but it makes sense to me.

Best Regards,

Bill "There's a fungus among us" Mattocks

Rodinal Addict · 08-20-2004

So, are these lenses able to be taken apart and cleaned? Is this a job for us mere mortals, or do I need any factory training?

bmattock · 08-20-2004

Quote:

Originally posted by Rodinal Addict
So, are these lenses able to be taken apart and cleaned? Is this a job for us mere mortals, or do I need any factory training?

Because the fungus grows between the lens elements, they must be disassembled and cleaned for proper removal. And even that may not work.

1) Some folks swear by the sunlight effect. Put the lens in a windowsill in direct sunlight for a couple of days. Should kill the fungus, and might dry it up to the extent that the damage is not as visible. I hear some folks say it works for some lenses some of the time. Your milage may vary.

2) Fungus gets in between cemented-together elements - this is bad. Lens elements used to be held together with a cement based on balsa-wood, and it is what the fungi are eating or have eaten. Therefore, chances are good that not only would you have to disassemble the lens, but also split a glued-together element to get at the fungi.

3) Fungus, once it eats, leaves an acidic residue that can and has etched glass - like a fossil in stone. Sometimes even removing the fungus will still leave a damaged lens behind. Probably no way to tell until you actually remove the fungus, either.

As mentioned on other threads here - many have tried to take apart lenses and been surprised when the aperture leaves fall out, little springs and ball bearing detents fly out, etc... Do you want to try this? Depends on the person. I've taken apart a few lenses and wrecked 'em by so doing. But they weren't much to begin with, so oh well.

There are some books on the subject - mentioned in the other thread current here on taking apart an Elmar lens. You might pick up the book and take a peek?

My general advice - most of us who are not particularly gifted mechanically don't want to do this.

Best Regards,

Bill Mattocks

Doug · 08-20-2004

Quote:

Originally posted by bmattock
2) Fungus gets in between cemented-together elements - this is bad. Lens elements used to be held together with a cement based on balsa-wood, and it is what the fungi are eating or have eaten. Therefore, chances are good that not only would you have to disassemble the lens, but also split a glued-together element to get at the fungi.

Good info, Bill! Just an incidental comment about the cement used in years past, not related to balsa wood, which of course is that very light wood from Central/South America used in model airplanes, for instance.

Now replaced by better synthetics, the old adhesive involved Canada balsam, which is a yellow oily turpentine extracted from the balsam fir tree, also used in paints and polishes. And perhaps yummy plant food for fungi. :-)

Laika · 08-21-2004

Quote:

Originally posted by Rodinal Addict
So, are these lenses able to be taken apart and cleaned? Is this a job for us mere mortals, or do I need any factory training?

What lens are we talking here? an Industar 26 or 61?.. I've found these very easy lenses to work on and I think you should have a go at cleaning them if you have some basic tools, what do you have to lose? Which side of the aperture blades is the fungus? ... If your interested to have a go yourself let me know and I could post some helpful stuff/pics one night next week.

ZeissFan · 08-21-2004

Any lens fungus should be removed. Either have the lens serviced or do the work yourself, but I most definitely would remove any spores or fungus on lens elements.

StillKicking · 03-21-2010

Fungal spores are found on and in almost all lenses, even straight from the factory. They are in the atmosphere, on your skin, your cloths, your camera bag.. everywhere!! What matters is whether they have the right conditions to germinate and grow. For that they need moisture and a source of food. On old lenses that used balsam based cements they had lots of food. More modern lens that use synthetic cements there is less food - but microbes don't need much to get a colony going.

If there is visible fungus you should:

(1) kill the fungus- exposure to UV light and in a dry atmosphere should do the trick
(2) use the lens to see if the image quality is affected - if not then keep an eye on it and keep the lens dry. The more you use a lens the more UV it is exposed to and the less likely you are to see fungus.
(3) if image quality is affected - have the lens cleaned (if it is economic to so) or throw it away. With FSU lenses it usually cheaper to replace the lens.

katcons · 03-21-2010

I was wondering from where you bought the lenses? I have a number of FSU lenses from Ukraine and they usually have separation marks, and not really fungi. Can you take a picture?

Ed S. · 03-21-2010

I've used cold-cream on camera leather and cases with very good success. My '80s vintage K-4 had a severe case of camera leather surface fungus on the body and the ever-ready case; fortunately, nowhere else.

A slight brushing to remove anything that was loose, then a very careful application to all leather followed by a rubdown over the rest of the camera and case (no glass surfaces), and the fungus and odor were gone. The leather was also rejuvinated; the case seems renewed, and I sort of trust the case strap (but it always seemed a bit thin).

I've applied the same treatment to a pair of Kiev-6c's and their cases, and a Salyut case, and with similar results.

I periodically rotate my lenses through a sunlight treatment, but I do it in Winter, when the lenses are much less likely to get hot and cause the internal lubricants to volatilize and coat the interior glass.

I recall reading about 1 week of sunlight as a treatment for yellowing (radioactive) Takumars; the instructions said to lightly wrap the lenses in aluminum foil to prevent overheating. I suspect that esposing the objective only and shading the rest of the lens might help prevent overheating.

I'm conflicted about throwing away lenses, even inexpensive FSU ones.

On one hand, dealing with an infected lens is imperative, since everything else is at risk. Add up the costs ......

OTOH, many times a cleaning is all that's needed, and metal-and-glass lenses are slowly becoming a thing of the past.

If the lens is a good one, a cleaning might be cheaper than getting a new one. If it also needs a re-lubing, or aperature repair, maybe it's still worth the cost. And sometimes a cleaning and proper reassembly turns a poor lens into a good one.

David Hughes · 03-23-2010

If you do decide to go in and fix it, then do the work on a tray lined with kitchen paper or a paper towel. That way, if you drop something the paper will stop it bouncing on to the floor and so should the sides of the tray.

The worst that can happen is that you wreck or damage a small screw and then have to get a replacement. And lens elements have a front and back. Make a careful note as you go along. People have been known to mark the side of the element with an arrow or letter "v" pointing to the front of the lens. But make sure the element doesn't turn over as you take it out.

There's several working drawings of USSR lenses on the www you just have to find the right one.

Regards, David

wolves3012 · 03-23-2010

I've found fungus in three lenses of purchased cameras, in every case it was an Industar 50 (2 on Zorkis and 1 on a Zenit). I stripped and cleaned them, soaking the elements in vinegar, then cleaned them with alcohol afterwards. With 2 of the lenses there was some etching of the coating on the inside face of the front element. This can't be seen after reassembly and doesn't appear to give problems. The biggest hassle in reassembly is keeping the elements clean (white cotton gloves!) and keeping dust out. Just needs some patience and care.

Elsewhere I've seen people say that vinegar can attack lens coatings but all I can say is that I had no issue there. It's not a strong acid, although it is corrosive. One of the ones I did required some persistence and even on that the coating was not damaged by the cleaning or vinegar.

As an aside, nothing to do with the fungus but one of the lenses did have a tiny flea (dead, unsurprisingly) between the groups!